The function of bumpstocks can be replicated by simply holding a semi-auto rifle loosely. The reason ATF didn’t ban them before is because there is no basis in law to do so. It will be very difficult to write a law banning them without making semi-auto rifles illegal.
If language used to ban bump stocks includes Feinsteins “rate increasing” devices it will lead to semi autos being banned. That is the intent.
Also Las Vegas looks too much like a False Flag op similar to Fast and Furious- which was an op to attack the 2nd Amendment by govt agents.